Wherever electrical circuits provide power to appliances, motors, and other equipment, it is desirable to electronically monitor the environment for hazardous conditions and, when detected, generate an audible alarm to warn people and protect property. For example, smoke detectors generate an audible alarm, but other detectors may warn of toxic fumes, motor overload, flammable gases, radon, carbon monoxide, fire, or other hazardous conditions. The invention will interrupt electric power to select circuits when it detects a hazardous condition alarm in order to prevent personal injuries, prevent fires, facilitate fire suppression, and protect property. The source of the alarm signal could be any audible, visible or invisible light, radio frequency, or other type signal, or combination of signals, generated by a device tuned to detect the presence of hazardous conditions. The invention may protect a power strip, wall outlet, or electrical panel circuit, or the invention may be integrated into the control circuitry of an individual appliance or machine.